1. Field of the Invention
The present invention relates to an electric-component (EC) mounting apparatus, and particularly to the art of controlling the upward and downward movements of a suction nozzle which sucks and holds an EC, in particular, an electronic component.
2. Discussion of Related Art
Japanese Patent Document No. 7-9381 discloses an EC mounting apparatus which includes a plurality of suction nozzles and an elevating and lowering device which elevates and lowers each of the suction nozzles to receive an EC from an EC supplying device and mounts the EC on a printed wiring board (PWB). This EC mounting apparatus additionally includes an index table which is rotatable about a vertical axis line and a plurality of EC mounting heads which are provided on the index table such that the EC mounting heads are equiangularly spaced from each other about the axis line. The index table is intermittently rotated, by an intermittently rotating device including a servomotor as its drive source, at the same angular pitch as that at which the EC mounting heads are spaced from each other, so that the heads are sequentially moved to, and stopped at, a plurality of stop positions including an EC-receive position and an EC-mount position.
Each of the EC mounting heads includes a nozzle holder and a suction nozzle which is held by the nozzle holder such that the suction nozzle is movable in an axial direction thereof, and is not rotatable, relative to the nozzle holder. The nozzle holder is held by the index table such that the holder is movable in an axial direction thereof relative to the table. Each of the EC mounting heads is elevated and lowered by each of two EC-mounting-head elevating and lowering devices which are provided at the EC-receive position and the EC-mount position, respectively, so that the each head receives an EC from the EC supplying device and mounts the EC on the PWB. Each of the EC-mounting-head elevating and lowering devices includes an elevator member and an elevator-member driving device. The elevator-member driving device includes, as its drive source, the servomotor of the intermittently rotating device, and additionally includes a lever which is connected to the elevator member, and a cam device which includes a cam and a cam follower and which converts the rotation of the servomotor into the pivotal motion of the lever, so that the elevator member is elevated and lowered.
In a state in which the elevator member is positioned at its upper-dead or upward-movement-end position, a lower surface of the elevator member is away from an upper surface of the nozzle holder of the EC mounting head being positioned the EC-receive or EC-mount position. Midway during the downward movement of the elevator member, the elevator member contacts the upper surface of the nozzle holder, thereby lowering the nozzle holder so that the suction nozzle sucks and holds an EC. When the elevator member is elevated, the nozzle holder is elevated, owing to the biasing action of a spring, to follow the elevator member. Before the elevator member reaches its upward-movement-end position, the nozzle holder reaches its upward-movement-end position and, in a state in which the elevator member has reached its upward-movement-end position, the elevator member is away from the nozzle holder. Thus, the nozzle holder is elevated or lowered while the holder is in contact with the elevator member but, in the state in which the elevator member is away from the holder, the holder is not elevated or lowered, and accordingly the suction nozzle is not elevated or lowered, even if the elevator member is elevated or lowered.
The length of the elevator member of the EC-mounting-head elevating and lowering device provided at the EC-receive position is adjustable, and accordingly the downward-movement-end position of each suction nozzle and the position where the decreasing of speed of downward movement of the each nozzle is started are changeable. The elevator member extends downward from a portion thereof connected to the lever, and the length of extension of the elevator member from the lever is adjustable by a length adjusting device. Thus, the length of the elevator member is adjustable, and accordingly the distance between the nozzle holder and the elevator member being positioned at its upward-movement-end position is changeable. That is, although the stroke of upward and downward movements of the elevator member is not changeable, the length of a portion of the stroke that is used to elevate and lower the nozzle holder is changeable, and accordingly the stroke of upward and downward movements of the holder is changeable. The upward-movement-end position of the nozzle holder held by the index table is not changeable, but the downward-movement-end position of the holder is changeable with the changing of the stroke thereof. This EC mounting apparatus detects a height position of an upper surface of each EC supplied by the EC supplying device and, if the detected height position is higher than a correct height position, the apparatus decreases the stroke of the nozzle holder and thereby changes the downward-movement-end position of the holder to a higher position. On the other hand, if the detected height position is lower than the correct height position, the apparatus increases the stroke of the nozzle holder and thereby changes the downward-movement-end position of the holder to a lower position. When the downward-movement-end position is changed, the downward-movement-deceleration-start position is also changed. Therefore, even if the height of the EC may have an error, the distance of downward movement of the suction nozzle is never too short or long. In addition, since the suction nozzle contacts the EC at a sufficiently low speed, the nozzle can reliably suck and hold the EC, without failing to hold the same or damaging the same.
The present invention provides EC mounting apparatus which has the following features. Those features are described, like claims, in respective paragraphs which are given respective numbers. Any feature that includes another feature shall do so by referring to the number given to the latter feature. However, the following features and the appropriate combinations thereof are just examples to which the technical features, and the combinations thereof, described in the specification are by no means limited. In addition, in the case where one feature recites a plurality of items, it is not essentially required that all of those items be simultaneously employed in the one feature. That is, it is possible to select and employ only a portion (one, two, . . . , but not all) of those items.
(1) According to a first feature of the present invention, there is provided an apparatus for mounting at least one electric component supplied by an electric-component supplying device, on a circuit substrate supported by a circuit-substrate supporting device, the apparatus comprising a nozzle moving device which moves a suction nozzle having an end surface that applies a suction to the electric component and thereby holds the component, in a direction intersecting an axis line of the suction nozzle; an elevating and lowering device which elevates and lowers the suction nozzle so that the suction nozzle performs at least one of receiving the electric component from the electric-component supplying device and mounting the component on the circuit substrate on the circuit-substrate supporting device; the elevating and lowering device comprising a movable member, and a connecting device which connects the movable member to the suction nozzle such that the suction nozzle continues moving while the movable member continues moving; and the connecting device comprising a downward-movement control device which changes, while the apparatus performs an electric-component mounting operation, at least one of a position of an end of a downward movement of the suction nozzle caused by the elevating and lowering device and a position where a deceleration of the downward movement of the nozzle is started.
In many cases, the suction nozzle is held by a nozzle holder such that the nozzle can be advanced and retracted relative to the holder. For example, the suction nozzle is held by the nozzle holder such that the nozzle is movable relative to the holder in the axial direction of the nozzle, and is biased by a spring member, such as a compression coil spring, in a direction in which the nozzle is advanced relative to the holder, and the limit of advancement of the nozzle is defined by an advancement-limit defining device. Accordingly, after the nozzle contacts an electric component (EC) supplied by the EC-supplying device or after the EC held by the nozzle contacts a circuit substrate supported by the circuit-substrate supporting device, the nozzle is retracted into the holder while elastically deforming the spring member. Thus, an excessive amount of downward movement of the nozzle holder is absorbed, and the nozzle or the EC is pressed against the EC or the substrate with an appropriate force. The spring member functions as a cushion device. In the case where the cushion device is employed, if the nozzle contacts the EC or if the EC contacts the substrate, then the nozzle is stopped and is not moved downward to a prescribed downward-movement end position, so that the nozzle or the EC is pressed against the EC or the substrate with a force which is substantially proportional to the difference between the prescribed downward-movement end position and the position where the nozzle is actually stopped. Thus, the downward-movement end position recited in the first feature (1) means the above-explained prescribed downward-movement end position, in other words, the position to which the nozzle is to be moved downward unless the nozzle is stopped. On the other hand, in the case where the cushion device is not employed, the respective amounts of downward movement of the nozzle holder and the suction nozzle are equal to each other, and accordingly the nozzle is moved downward to the prescribed downward-movement end position. In the former case where the cushion device is employed, if the nozzle sucks and holds an EC without pressing the EC, the respective amounts of downward movement of the holder and the nozzle are equal to each other. For example, if, when the holder reaches its downward-movement end position, the nozzle just contacts the EC and holds the same without elastically deforming the spring member, or if, when the holder reaches its downward-movement end position, the nozzle is positioned at a small distance from the EC and holds the same without elastically deforming the spring member, then the respective amounts of downward movement of the holder and the nozzle are equal to each other, and the nozzle sucks and holds the EC without pressing the same.
The nozzle moving device may be a positioning device which moves the suction nozzle and stops the nozzle at at least one of an EC-receive position where the nozzle receives an EC from the EC supplying device and an EC-mount position where the nozzle mounts the EC on a circuit substrate supported by the circuit-substrate supporting device; a selecting device which selects, from a plurality of suction nozzles, one suction nozzle which is to be used to receive and mount an EC; or a device which has both the positioning function and the selecting function. In the case where the nozzle moving device positions the suction nozzle relative to the circuit substrate, the nozzle moving device also functions as an EC transferring device which moves the suction nozzle holding the EC and thereby transfers the EC.
While the movable member of the elevating and lowering device is moved, the suction nozzle is moved. In the case where the above-described cushion device is employed, the suction nozzle may not be moved downward to the prescribed downward-movement end position, i.e., may be stopped midway, because the downward movement is hindered by the EC or the circuit substrate. If the downward movement is not hindered, then the suction nozzle would continue moving downward. Thus, it can be said that while the movable member is moved, the suction nozzle is moved.
According to the first feature (1), each portion of the movement of the movable member is used to move the suction nozzle and, while the present EC mounting apparatus performs an EC mounting operation, at least one of the downward-movement end position of the nozzle and the position where the deceleration of the downward movement of the nozzle is started is changed. Therefore, even if there may be an error of a position of an end portion of the nozzle and/or an error of a thickness of an EC, the present apparatus can appropriately control at least one of receiving the EC or mounting the EC. For example, if the downward-movement end position of the nozzle is changed, then a shortage or an excessiveness of amount of downward movement of the nozzle can be avoided, and accordingly an EC can be sucked and held by the nozzle while a failure to hold the EC or braking the EC is avoided, or an EC can be mounted on a circuit substrate while a failure to mount the EC or damaging the EC is avoided. Even if the nozzle may have a nominal-dimension difference, a manufacturing error, and/or wearing, the present apparatus can accurately control the nozzle to suck and hold an EC while applying an appropriate pressing force to the EC, or while just contacting the EC with a pressing force substantially equal to zero, or while having a prescribed distance to the EC.
(2) According to a second feature of the present invention that includes the first feature (1), the nozzle moving device stops the suction nozzle at a prescribed position, and the elevating and lowering device is provided in a vicinity of the prescribed position and lowers, at at least the prescribed position, the suction nozzle to the position of the end of the downward movement thereof.
The elevating and lowering device may be one which elevates and lowers the suction nozzle after the nozzle reaches, and stops at, a stop position, or one which starts elevating or lowering the nozzle before the nozzle reaches a stop position.
According to the second feature (2), the suction nozzle is moved relative to the elevating and lowering device. For example, in the case where the nozzle moving device positions the nozzle at at least one of the EC-receive position and the EC-mount position, the elevating and lowering device is provided in the vicinity of the one of the EC-receive position and the EC-mount position. In the case where the nozzle moving device selects, from a plurality of suction nozzles, one suction nozzle, moves the one nozzle, and positions the one nozzle at an operative position where the one nozzle is used to receive and mount an EC, the elevating and lowering device is provided in the vicinity of the operative position. In either case, the elevating and lowering device may be commonly used for a plurality of suction nozzles, and accordingly it is often needed to change at least one of the downward-movement end position and downward-movement-deceleration-start position of each nozzle, to compensate for differences of respective nominal dimensions of the nozzles and/or errors of respective lengths of the nozzles resulting from a manufacturing error or wearing of each of the nozzles. Thus, according to the second feature (2), the present invention is very effective. In addition, since the suction nozzle is moved relative to the elevating and lowering device, it is needed to operate the elevating and lowering device and thereby elevate and lower the nozzle, in a good timed relation with the movement and stopping of the nozzle. To this end, the fourth feature (4) is very effective.
(3) According to a third feature of the present invention that includes the second feature (2), the nozzle moving device comprises a nozzle revolving device which revolves the suction nozzle about an axis line and stops the nozzle at a prescribed stop position on a locus of revolution thereof.
The axis line of revolution may be a vertical axis line or may be an axis line inclined relative to a vertical plane.
The nozzle revolving device may be one which intermittently revolves the suction nozzle at a prescribed regular angular pitch, or one which revolves the nozzle by an arbitrary angle. Otherwise, the nozzle revolving device may be one which revolves the nozzle in one direction only, or one which revolves the nozzle in each of opposite directions.
(4) According to a fourth feature of the present invention that includes any one of the first to third features (1) to (3), the apparatus further comprises a common drive source which commonly drives the nozzle moving device and the elevating and lowering device.
In the case where the elevating and lowering device includes an exclusive drive source, the downward-movement end position, or the like, of the suction nozzle can be considerably easily controlled by controlling the exclusive drive source. In contrast, in the case where the elevating and lowering device shares a drive source with the nozzle moving device, the amount of movement of the suction nozzle caused by the nozzle moving device may be changed if the operation of the drive source is modified to change the downward-movement end position, or the like, of the nozzle. Therefore, conventionally, it has not been practiced to change, while an EC mounting apparatus of this sort performs an EC mounting operation, the downward-movement end position, or the like, of a suction nozzle. However, since the connecting device which connects the suction nozzle to the movable member which is driven by the common drive source includes the downward-movement control device, the present apparatus can change, while performing an EC mounting operation, the downward-movement end position, or the like, of the nozzle.
(5) According to a fifth feature of the present invention that includes the fourth feature (4), the downward-movement control device comprises a stroke changing device which changes the movement of the movable member into an arbitrary one of a plurality of different strokes of the downward-movement of the suction nozzle.
The downward-movement control device may be one which shifts the stroke of the suction nozzle as a whole by changing both the upward-movement and downward-movement end positions of the nozzle. However, it is easier to change the downward-movement end position by changing the stroke.
Here, the plurality of different strokes do not include a stroke equal to zero.
The stroke may be stepwise changed, or continuously changed. In the latter case, it is can be said that the stroke is changed to any one of an infinite number of different lengths.
(6) According to a sixth feature of the present invention, there is provided an apparatus for mounting at least one electric component supplied by an electric-component supplying device, on a circuit substrate supported by a circuit-substrate supporting device, the apparatus comprising a nozzle revolving device which revolves, about an axis line, a suction nozzle having an end surface that applies a suction to the electric component and thereby holds the component, so that the suction nozzle transfers the component; an elevating and lowering device which elevates and lowers the suction nozzle so that the suction nozzle performs at least one of receiving the electric component from the electric-component supplying device and mounting the component on the circuit substrate on the circuit-substrate supporting device; a common drive source which commonly drives the nozzle revolving device and the elevating and lowering device; the elevating and lowering device comprising a movable member, and a connecting device which connects the movable member to the suction nozzle such that the suction nozzle continues moving while the movable member continues moving; and the connecting device comprising a downward-movement control device which changes, while the apparatus performs an electric-component mounting operation, at least one of a position of an end of a downward movement of the suction nozzle caused by the elevating and lowering device and a position where a deceleration of the downward movement of the nozzle is started.
(7) According to a seventh feature of the present invention that includes any one of the first to fourth and sixth features (1) to (4) and (6), the elevating and lowering device comprises a cam device which includes a rotary cam which is rotated by a drive source, and a cam follower which is engaged with the rotary cam.
The cam device can accurately control the downward movement of the suction nozzle. For example, the cam device can move downward the nozzle at a high speed and smoothly decrease the speed in a terminal portion of the downward movement, so that the nozzle can contact an EC, or an EC held by the nozzle can contact a circuit substrate, with a small impact. In addition, the cam device can lower the nozzle in an accurately timed relation with a movement of the nozzle to a stop position. However, usually, the motion of the cam follower of the cam device is a prescribed motion, and accordingly it is very difficult to change the downward-movement end position, or the like, of the nozzle based on an error of a position of an end portion of the nozzle or an error of a thickness of each EC. According to the present invention, the upward and downward-movement of the nozzle is controlled by the cam device, on one hand, and the downward-movement end position, or the like, of the nozzle can be changed, on the other hand.
In particular, in the case where the nozzle moving device and the elevating and lowering device share a drive source, the operation of the elevating and lowering device can be easily synchronized with the operation of the nozzle moving device, by employing the cam device. Thus, the suction nozzle can be moved at a high speed, and at least one of receiving each EC and mounting the same can be performed at a high speed and with a high accuracy.
(8) According to an eighth feature of the present invention that includes the seventh feature (7), the movable member comprises the cam follower, and the downward-movement control device comprises a stroke changing device which changes the movement of the cam follower into an arbitrary one of a plurality of different strokes of the downward-movement of the suction nozzle.
Here, the plurality of different strokes does not include a stroke equal to zero.
(9) According to a ninth feature of the present invention that includes the fifth or eighth feature (5) or (8), the stroke changing device changes the position of the end of the downward movement of the suction nozzle, while not changing a position of an end of an upward movement of the nozzle.
(10) According to a tenth feature of the present invention that includes any one of the first to seventh features (1) to (7), the apparatus further comprises an elevator member which is connected to the suction nozzle, and the downward-movement control device comprises a lever which is pivotable about an axis line and has an arm; a first movable member which is supported by the arm of the lever such that the first movable member is movable relative to the arm in a lengthwise direction of the arm, the first movable member being connected to the elevator member; and a first-movable-member moving device which moves the first movable member in the lengthwise direction of the arm.
(11) According to an eleventh feature of the present invention, there is provided an apparatus for mounting at least one electric component supplied by an electric-component supplying device, on a circuit substrate supported by a circuit-substrate supporting device, the apparatus comprising a nozzle moving device which moves a suction nozzle having an end surface that applies a suction to the electric component and thereby holds the component, in a direction intersecting an axis line of the suction nozzle; an elevating and lowering device which elevates and lowers the suction nozzle so that the suction nozzle performs at least one of receiving the electric component from the electric-component supplying device and mounting the component on the circuit substrate on the circuit-substrate supporting device; an elevator member which is connected to the suction nozzle; a downward-movement control device which changes, while the apparatus performs an electric-component mounting operation, at least one of a position of an end of a downward movement of the suction nozzle caused by the elevating and lowering device and a position where a deceleration of the downward movement of the nozzle is started; and the downward-movement control device comprising a lever which is pivotable about an axis line and has an arm; a first movable member which is supported by the arm of the lever such that the first movable member is movable relative to the arm in a lengthwise direction of the arm, the first movable member being connected to the elevator member; and a first-movable-member moving device which moves the first movable member in the lengthwise direction of the arm.
The elevator member and the suction nozzle may be connected to each other in such a manner that the nozzle moves while the elevator member moves, or a manner that the nozzle may not move while the elevator member moves, that is, the nozzle may is moved based on a portion of the movement of the elevator member. In either manner, the elevator member is connected to the arm via the first movable member and, when the arm is pivoted, the elevator member is moved. In addition, when the first movable member is moved in the lengthwise direction of the arm, the distance between the axis line of pivotal motion of the lever and the position where the elevator member is connected to the arm is changed, and accordingly a lever ratio, i.e., a ratio of the rotation angle of the lever to the distance of movement of a portion of the elevator member that is connected to the arm is changed. Thus, the stroke of movement of the elevator member is changed, and accordingly the stroke of upward and downward movement of the suction nozzle is changed.
The EC mounting apparatus according to the eleventh feature (11) may employ any one of the above-described first to ninth features (1) to (9).
(12) According to a twelfth feature of the present invention that includes the tenth or eleventh feature (10) or (11), the first-movable-member moving device comprises a second-movable-member guide which is substantially parallel to the lengthwise direction of the arm of the lever; a second movable member which is movable along the second-movable-member guide; a second-movable-member drive device which moves the second movable member along the second-movable-member guide; and an engaging device which includes a first engaging portion which is provided by at least a portion of the first movable member, and a second engaging portion which is provided by at least a portion of the second movable member, the first and second engaging portions having respective shapes which transmit a movement of the second movable member along the second-movable-member guide to the first movable member and allow a movement of the first movable member caused by a pivotal motion of the lever.
If the first movable member and an output member of the first-movable-member moving device are connected to each other by a connecting rod, such that opposite end portions of the connecting rod are pivotally connected to the first movable member and the output member, respectively, the first-movable-member moving device can move the first movable member in the lengthwise direction of the arm, while allowing the movement of the first movable member caused by the pivotal motion of the lever. In this case, however, it is needed to locate the first-movable-member moving device at a position distant from the first movable member. In contrast, the engaging device recited in the twelfth feature (12) enables the first-movable-member moving device to be located at a position in the vicinity of the arm, which leads to constructing the downward-movement control device in a compact manner.
(13) According to a thirteenth feature of the present invention that includes the eleventh or twelfth feature (11) or (12), the apparatus further comprises a connecting rod which is pivotally connected, at one of opposite end portions thereof, to the first movable member and is pivotally connected, at the other end portion thereof, to the elevator member, and thereby connects the first movable member and the elevator member to each other.
(14) According to a fourteenth feature of the present invention that includes the thirteen feature (13), the downward-movement control device further comprises a first-movable-member guide which is curved along an arc whose center is located on an axis line about which the other end portion of the connecting rod is pivoted relative to the elevator member being positioned at a position of an end of an upward movement thereof caused by the elevating and lowering device.
Whichever position the first movable member may take on the first-movable-member guide, the axis line about which the other end portion of the connecting rod is pivoted is positioned at the center of the arcuate guide, in the state in which the elevator member is positioned at its upward-movement end position. Thus, if the stroke of upward and downward movement of the elevator member is changed, the upward-movement end position of the same is not changed, and the downward-movement end position of the same is changed.
(15) According to a fifteenth feature of the present invention that includes the fourteenth feature (14), the second-movable-member guide extends along a straight line, and the second-movable-member drive device comprises a position determining means for determining, based on a target downward-movement-end position of the suction nozzle, a position of the second movable member.
It is possible to employ a curved second-movable-member guide which is curved parallel to the curved first-movable-member guide. In contrast, a linear second-movable-member guide which extends along a straight line contributes to simplifying the construction of the second-movable-member drive device itself or that of a drive-force transmitting device which transmits the drive force of the drive device to the second movable member. In the latter case, however, the amount of operation of the drive device is not regularly proportional to the amount of movement of the suction nozzle. Hence, it is preferred that the drive device itself include a position determining means for determining, based on a target downward-movement-end position of the nozzle, a position of the second movable member. In the last case, the present apparatus can be used more easily.
(16) According to a sixteenth feature of the present invention that includes any one of the first to fifteenth features (1) to (15), the downward-movement control device comprises a memory which stores control data; and a control-data-depending determining means for determining, based on the control data stored in the memory, the at least one of the position of the end of the downward movement of the suction nozzle and the position where the deceleration of the downward movement of the nozzle is started.
The control data may be data which are obtained in advance, and stored in the memory, before an EC-mounting operation is started, or data which are obtained, and stored in the memory, during an EC-mounting operation. In addition, the control data may be data which are automatically obtained and stored in the memory, or data which are manually obtained, and stored in the memory, by an operator.
Respective positional errors of the nozzle holder, the EC-supplying device, and the circuit-substrate supporting device relative to one another (in particular, their height-positional errors with respect to a vertical direction), resulting from respective errors of various constituent devices and members of the EC mounting apparatus, are corrected when those devices and members are assembled into the apparatus. And yet the suction nozzle may fail to suck or mount an EC, because there are not only some errors which cannot be corrected by correcting the positional errors of the apparatus, but also some nominal-dimension differences. For example, replaceable elements relating the EC mounting apparatus, such as ECs, circuit substrates, suction nozzles, or EC-supply feeders, have not only manufacturing errors, but also nominal-dimension differences among manufacturing companies. In addition, in the case where the EC mounting apparatus employs a plurality of sorts of suction nozzles, and mounts a plurality of sorts of ECs on a circuit substrate, those nozzles and those ECs have nominal-dimension differences. Therefore, if those errors and those nominal-dimension differences are obtained and stored in advance and the upward and downward movement of the suction nozzle is controlled based on those data, it is possible to reduce the chance of occurrence of failure to suck or mount an EC. The control-data-depending determining means can be said as a given-data-depending determining means.
(17) According to a seventeenth feature of the present invention that includes any one of the first to sixteenth features (1) to (16), the downward-movement control device comprises an error detecting device which detects at least one of an error of a position of an end surface of the suction nozzle that applies the suction, an error of a position of an upper surface of the electric component supported by a component-supply portion of the electric-component supplying device, an error of a position of a mounted surface of the electric component held by the suction nozzle that is to be mounted on the circuit substrate supported by the circuit-substrate supporting device, and an error of a position of a support surface of the circuit substrate that is to support the electric component mounted thereon; and a detected-error-depending determining means for determining, based on the error detected by the error detecting device, the at least one of the position of the end of the downward movement of the suction nozzle and the position where the deceleration of the downward movement of the nozzle is started.
The error of the position of the end surface of the suction nozzle may be produced by a manufacturing error of the nozzle, or wearing of the end surface. The error of the position of the upper surface of each EC supported by the EC-supply portion of the EC supplying device may be directly detected, or may be determined as the sum of a positional error of the EC-supply portion and a thickness error of the each EC. In the case where it can be assumed that one of the position of the EC-supply portion and the thickness of each EC has no error, the error of the position of the upper surface of the each EC can be determined based on only the error of the other of the position of the EC-supply portion and the thickness of the each EC. The error of the position of the mounted surface of each EC held by the suction nozzle that is to be mounted on the circuit substrate may be directly detected, or may be determined as the sum of a positional error of the end surface of the nozzle and a thickness error of the each EC. In the case where it can be assumed that one of the position of the end surface of the nozzle and the thickness of each EC has no error, the error of the position of the mounted surface of the each EC can be determined based on only the error of the other of the position of the end surface and the thickness of the each EC. The error of the position of the support surface of the circuit substrate supported by the circuit-substrate supporting device may be directly detected, or may be determined as the sum of a positional error of a circuit-substrate-support surface of the circuit-substrate supporting device and a thickness error of the circuit substrate. In the case where it can be assumed that one of the position of the circuit-substrate-support surface and the thickness of the circuit substrate has no error, the error of the position of the support surface of the circuit substrate can be determined based on only the error of the other of the position of the circuit-substrate-support surface and the thickness of the circuit substrate.
If, based on at least one of the positional error of the end surface of the suction nozzle and the positional error of the upper surface of each EC supported by the EC-supply portion of the EC supplying device, at least one of the downward-movement-end position and downward-movement-deceleration-start position of the nozzle is determined, the nozzle is effectively prevented from failing to suck and hold the each EC. In addition, if, based on at least one of the positional error of the mounted surface of each EC held by the suction nozzle and the positional error of the support surface of the circuit substrate supported by the circuit-substrate supporting device, at least one of the downward-movement-end position and downward-movement-deceleration-start position of the nozzle is determined, the nozzle is effectively prevented from failing to mounting the each EC on the circuit substrate.
At least one of the above-indicated errors may be obtained, and stored in the memory, before an EC-mounting operation is started, or may be obtained, and stored in the memory, during an EC-mounting operation. In the former case, the detected-error-depending determining means also functions as a given-data-depending determining means.
According to the seventeenth feature (17), even if the EC mounting apparatus may not include the given-data-depending determining means, the apparatus can reduce the number of failures to suck or mount ECs, by controlling the upward and downward movements of the suction nozzle based on the error detected by the error detecting device. On the other hand, if the apparatus includes the given-data-depending determining means, the apparatus can control the upward and downward movements of the nozzle based on not only the detected error but also the nominal-dimension differences, etc., and thereby minimize the number of failures to suck or mount ECs.